Is there any automatic way of lowering quality of imported subd meshes? I would like to have less points on surfaces.

After importing whole set of models MoI freezes during booleans. Every mesh is ok but I would like to go lower with quality of surfaces a bit to get workable level.

Is it possible?

This ?

I don`t want change shape of object I would like only delete some points from surface in MoI after Subd conversion (for example delete every second points row from surface).

I know that but I use Zbrush Zremesher. I`ve heard it`s better.

Hi mdesign, the main way would be to not have a dense sub-d cage with a lot of little polygons in it.

But also there is a setting under Options > Import/Export > SubD import options > "Patch type = More patches, fewer control points". That will make for smaller patches around non-valence 4 points but also less control points.

If you have a lot of little polygons in your sub-d cage though that makes for a complex result, each control polygon becomes a NURBS surface fragment. To get a simpler result you need a coarser control cage not a heavy and very detailed one.

- Michael

Hi mdesign,

re:
> I don`t want change shape of object I would like only delete some points from surface in MoI after
> Subd conversion (for example delete every second points row from surface).

Sorry no there aren't any tools for surface simplification like that in MoI. The Sub-d converter assumes that you will have formed the sub-d control cage how you need it. If you want a simpler result you need to have a simpler control cage.

If you just kind of randomly delete rows of NURBS surface control points it would likely introduce various kinds of lumps and shape mutations. It would change the shape.

- Michael

Thanks Michael. I`ve already have got that option enabled. There is no option to go lower than that.
Those small polygons are only on corners (baked fillets - additional loops on hard corners).

Today I`ve thought that I will do ONLY booleans in MoI and next I will do mold for that part (aslo in MoI).

My final object are build from many small subd objects which are added, substracted and intersected with each other.
I`ve thought to import all AS IS in subd and do only that booleans operations which will allow me to rebuild my subd model without rebuilding it in nurbs.

In that idea I don`t need MoI fillets, blending and thickening. I need do only booleans.

But its about 20 big subd objects with small creases = big dense objects inside MoI.

That`s why I had idea to lighten it more. I`ve gave up with filleting and thickening.

But it`s still very heavy for MoI eaven if meshes are not high poly (because of creases).

I`ve thought that wire is low but now I can see that always edge loops on creases = dense nurbs mesh even if cage is low poly.

Edit: My first sentence is wrong. That density of mesh is similar even without additional edge loops on creases (dense).

but why you don't use _ImportOBJ by Max Smirnov ?
Seems you have just only the patch points ? Or i miss something! :)



One Subdive


Two subdive

I assumed that is same engine (algorithm). My bad. You are right. Importing it as Obj and manually subdivide it, is not same as import as subdivided obj.

Brilliant. Thanks a lot :)

Hi mdesign,

re:
> Thanks Michael. I`ve already have got that option enabled. There is no option to go lower than that.

No, from what your screenshots above show you do not have that option enabled.

The one on the left has "Patch type = Fewer patches, more control points" (the default), the one on the right has "More patches, fewer control points":



The one on the left has 34 surfaces, the one on the right has 94 surfaces. The difference is in how non-valence-4 vertices are handled (which require a higher degree surface).

The default mode will form large patches radiating out from the extraordinary vertices, but this means that those larger surfaces will have a higher degree:


The other mode will prioritize making large patches by gluing together regular valence-4 areas, those can use a lower degree 3 surface. The higher degree surfaces right around an extraordinary vertex will be kind of walled off and so you will have a more fragmented topology with smaller pieces but with a lot less control points for regular areas:


- Michael

Thanks, you are right.

Hi mdesign,

> I`ve thought that wire is low but now I can see that always edge loops on creases = dense nurbs mesh even if cage is low poly.
>
> Edit: My first sentence is wrong. That density of mesh is similar even without additional edge loops on creases (dense).

It's not directly so much about the additional edge loops themselves, it's having quite a bunch of extraordinary vertices. Those are vertices that have other than 4 edges coming out from them.

Some things that would probably help would be to reduce the amount of those in the mesh, and also try to reduce the size of the polygons directly around them while using "More patches, fewer control points" patch combining mode.

- Michael

Hi mdesign,

re:
> I assumed that is same engine (algorithm). My bad. You are right. Importing it as Obj and manually
> subdivide it, is not same as import as subdivided obj.

They are totally different algorithms and engines. One of the main areas where they are different is in how extraordinary vertices are handled. In the older one (and in all other converters that I've tested myself) there are surface continuity breaks at extraordinary vertices. MoI's OBJ converter is able to handle those better and make totally smooth surfaces across extraordinary vertices. However it needs to use higher degree surfaces in those spots to do that, the higher degree surfaces will have denser control points but you can adjust that by the SubD import options > "Patch type" option to switch the priority from nicer topology to lower surface control point density.

- Michael

Hi mdesign,

re:
> Today I`ve thought that I will do ONLY booleans in MoI and next I will do mold for that part (aslo in MoI).

I would think it should be possible to do this. Here's an example that I made with 50 copies of your feather, boolean calculation time 30 seconds on my pretty old machine:



If you're running into problems and need help I will need to be able to load the models you are working with over here to be able to give you more advice.

- Michael

For now I`m sure that is possible to do my boolean job in MoI. I had main problem with heavy load and lag but after your deep explanation I will lower density to have better performance in MoI.

My current mesh in work includes about 20 different cutters and adders. Some of them are triangulated. I need to change them to subd and then I will do great test in MoI. Next I will build mold over it inside MoI with keeping my draft angles with Cplanes (in Modo it names workplanes).

Thank Michael for your oustanding help.